3D Analysis of Fracture Patterns Affecting an Outcropping Anticline - Inferences for Similar Buried Reservoirs

摘要

Anticlines are common structural hydrocarbon traps and are often fractured. Outcrops help in improving the characterization of fracture networks. New methods developed for the acquisition of fracture data from pavements and vertical outcrops allow for a full characterization of the spatial organization of fractures in the Tata anticline (central Morocco). Three sets of fractures are observed perpendicular, parallel and oblique to the fold axis. The first two groups have few tens of metres long joints; none of them can be followed across the entire anticline. Spacing distances are <0.8 m for the fold-axis parallel set and between 0.5 and 2 meters for the set perpendicular to the fold axis. The oblique set is composed of shorter features arranged in corridors. In the vertical dimension, fractures are always less high than the thickness of the multilayer. Highest densities are found at the top and the bottom of the succession and changes are gradual suggesting that the single layers are mechanically coupled and that it is the entire multilayer which acts as a mechanical unit.